Spike is absolutely sure they're not supposed to be down here. He just doesn't care. And he doesn't snuff out his cigarette, not yet. Not like he's going to start a fire, unless the ankle-deep blood and muck down here is somehow flammable. Probably. If it is flammable they're all fucked anyway so what's one more cigarette?

"You hear that?" Spike asked when he heard the sound as well. Like a far-off cry. He heads directly for it.